National 710663 Transfer Case Output Shaft Seal - Rear

National Transfer Case Output Shaft Seal Overview

The National 710663 transfer case output shaft seal is engineered to provide reliable sealing performance for select Hummer and Jeep models. Designed with a bi-directional lip and fluoro-elastomer material, this oil seal helps maintain transfer case integrity by preventing fluid leaks and contamination.

• Compatible with Hummer H1 and Jeep Cherokee, Grand Cherokee, TJ, and Wrangler models
• Part number 710663 for precise identification
• Bi-directional lip design for effective sealing in both rotational directions
• Constructed from durable fluoro-elastomer sealing material
• Inside diameter approximately 1.177 inches (29.9 mm) and outside diameter around 2.587 inches (65.7 mm)
• Thickness of 0.433 inches (11 mm) with overall width including side lip of 0.630 inches (16 mm)
• Fits housing bore size near 2.578 inches (65.5 mm)

Technical Details and Specifications

This National transfer case output shaft seal (part number 710663) is part of the 710600 series and features a bi-directional lip design that ensures effective sealing under varying rotational forces. The seal’s fluoro-elastomer construction offers resistance to heat, oil, and wear, making it suitable for demanding transfer case environments. With an inside diameter of 1.177 inches (29.9 mm) and an outside diameter of 2.587 inches (65.7 mm), it fits precisely into the housing bore of approximately 2.578 inches (65.5 mm). The thickness of 0.433 inches (11 mm) and overall width including the side lip of 0.630 inches (16 mm) provide a secure fit and reliable sealing surface.

Applications and Problem Solving

This transfer case output shaft seal is designed for use in the transfer cases of specific Hummer and Jeep vehicles, including the H1, Cherokee, Grand Cherokee, TJ, and Wrangler. It addresses common issues such as:

• Preventing transfer case fluid leaks that can lead to component damage
• Reducing contamination from dirt and debris entering the transfer case
• Maintaining proper lubrication within the transfer case output shaft area
• Minimizing wear on the output shaft and surrounding components
• Ensuring consistent transfer case performance and longevity

Installation Notes and Tips

When installing the National 710663 transfer case output shaft seal, ensure the housing bore is clean and free of debris. Use appropriate tools to avoid damaging the seal during installation. Verify the seal’s orientation matches the bi-directional lip design for optimal sealing. Lubricate the seal lip lightly with transfer case fluid before installation to reduce initial wear. Check for proper fitment with the shaft diameter of approximately 1.181 inches (30 mm) to ensure a secure seal.

Quality Assurance and Warranty

National transfer case seals are manufactured to meet industry standards for durability and performance. The fluoro-elastomer material provides resistance to heat and chemical degradation, supporting long service life. Part number 710663 is backed by National’s quality control processes, ensuring consistent product reliability. Warranty coverage details should be confirmed with the product documentation or manufacturer.